The organization says it's also bad for the environment. How? It involves the almost 2 trillion pounds of animal waste produced annually in the U.S., according to The Food Animal Concerns Trust.

Up to 75 percent of an antibiotic can pass through an animal, so when that waste gets deposited, so do the antibiotics and the now-resistant bacteria. That bacteria then risks being transfered to humans through surface and ground waters as well as through manure used to farm vegetables and fruits. (Video via Natural Resources Defense Council)

Relying less on antibiotics in livestock could also help reduce the number of infections in humans. The CDC reports around 2 million Americans get antibiotic-resistant infections a year, and 23,000 of those people die.